Make the library usable as a library.

- Add namespace unwindstack everywhere so that it's easier for other
  code to use the library.
- Move some of the header files into include/unwindstack so that they
  can be exposed.
- Modify the headers so that only a limited number need to be exposed.
- Update the tools to use the new headers.
- Add a GetLoadBias() call on the Elf object. This prevents the need
  to get the interface object out of the Elf object.
- Move the GetRelPc() call out of the Reg class, to the Elf class. It's
  not always the case that a Reg object will be around when you want to
  get a relative pc. The tests for this moved to ElfTest.cpp.

Bug: 23762183

Test: Unit tests pass.
Change-Id: Iac609dac1dd90ed83d1a1e24ff2579c96c023bc3

1 files changed, 173 insertions, 0 deletions

diff --git a/libunwindstack/include/unwindstack/ElfInterface.h b/libunwindstack/include/unwindstack/ElfInterface.h
new file mode 100644
index 0000000..5cac0d3
--- /dev/null
+++ b/libunwindstack/include/unwindstack/ElfInterface.h
@@ -0,0 +1,173 @@
+/*
+ * Copyright (C) 2016 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef _LIBUNWINDSTACK_ELF_INTERFACE_H
+#define _LIBUNWINDSTACK_ELF_INTERFACE_H
+
+#include <elf.h>
+#include <stdint.h>
+
+#include <memory>
+#include <string>
+#include <unordered_map>
+#include <vector>
+
+#include <unwindstack/DwarfSection.h>
+
+namespace unwindstack {
+
+// Forward declarations.
+class Memory;
+class Regs;
+class Symbols;
+
+struct LoadInfo {
+  uint64_t offset;
+  uint64_t table_offset;
+  size_t table_size;
+};
+
+enum : uint8_t {
+  SONAME_UNKNOWN = 0,
+  SONAME_VALID,
+  SONAME_INVALID,
+};
+
+class ElfInterface {
+ public:
+  ElfInterface(Memory* memory) : memory_(memory) {}
+  virtual ~ElfInterface();
+
+  virtual bool Init() = 0;
+
+  virtual void InitHeaders() = 0;
+
+  virtual bool GetSoname(std::string* name) = 0;
+
+  virtual bool GetFunctionName(uint64_t addr, std::string* name, uint64_t* offset) = 0;
+
+  virtual bool Step(uint64_t rel_pc, Regs* regs, Memory* process_memory);
+
+  Memory* CreateGnuDebugdataMemory();
+
+  Memory* memory() { return memory_; }
+
+  const std::unordered_map<uint64_t, LoadInfo>& pt_loads() { return pt_loads_; }
+  uint64_t load_bias() { return load_bias_; }
+  void set_load_bias(uint64_t load_bias) { load_bias_ = load_bias; }
+
+  uint64_t dynamic_offset() { return dynamic_offset_; }
+  uint64_t dynamic_size() { return dynamic_size_; }
+  uint64_t eh_frame_offset() { return eh_frame_offset_; }
+  uint64_t eh_frame_size() { return eh_frame_size_; }
+  uint64_t debug_frame_offset() { return debug_frame_offset_; }
+  uint64_t debug_frame_size() { return debug_frame_size_; }
+  uint64_t gnu_debugdata_offset() { return gnu_debugdata_offset_; }
+  uint64_t gnu_debugdata_size() { return gnu_debugdata_size_; }
+
+  DwarfSection* eh_frame() { return eh_frame_.get(); }
+  DwarfSection* debug_frame() { return debug_frame_.get(); }
+
+ protected:
+  template <typename AddressType>
+  void InitHeadersWithTemplate();
+
+  template <typename EhdrType, typename PhdrType, typename ShdrType>
+  bool ReadAllHeaders();
+
+  template <typename EhdrType, typename PhdrType>
+  bool ReadProgramHeaders(const EhdrType& ehdr);
+
+  template <typename EhdrType, typename ShdrType>
+  bool ReadSectionHeaders(const EhdrType& ehdr);
+
+  template <typename DynType>
+  bool GetSonameWithTemplate(std::string* soname);
+
+  template <typename SymType>
+  bool GetFunctionNameWithTemplate(uint64_t addr, std::string* name, uint64_t* func_offset);
+
+  virtual bool HandleType(uint64_t, uint32_t) { return false; }
+
+  Memory* memory_;
+  std::unordered_map<uint64_t, LoadInfo> pt_loads_;
+  uint64_t load_bias_ = 0;
+
+  // Stored elf data.
+  uint64_t dynamic_offset_ = 0;
+  uint64_t dynamic_size_ = 0;
+
+  uint64_t eh_frame_offset_ = 0;
+  uint64_t eh_frame_size_ = 0;
+
+  uint64_t debug_frame_offset_ = 0;
+  uint64_t debug_frame_size_ = 0;
+
+  uint64_t gnu_debugdata_offset_ = 0;
+  uint64_t gnu_debugdata_size_ = 0;
+
+  uint8_t soname_type_ = SONAME_UNKNOWN;
+  std::string soname_;
+
+  std::unique_ptr<DwarfSection> eh_frame_;
+  std::unique_ptr<DwarfSection> debug_frame_;
+
+  std::vector<Symbols*> symbols_;
+};
+
+class ElfInterface32 : public ElfInterface {
+ public:
+  ElfInterface32(Memory* memory) : ElfInterface(memory) {}
+  virtual ~ElfInterface32() = default;
+
+  bool Init() override {
+    return ElfInterface::ReadAllHeaders<Elf32_Ehdr, Elf32_Phdr, Elf32_Shdr>();
+  }
+
+  void InitHeaders() override { ElfInterface::InitHeadersWithTemplate<uint32_t>(); }
+
+  bool GetSoname(std::string* soname) override {
+    return ElfInterface::GetSonameWithTemplate<Elf32_Dyn>(soname);
+  }
+
+  bool GetFunctionName(uint64_t addr, std::string* name, uint64_t* func_offset) override {
+    return ElfInterface::GetFunctionNameWithTemplate<Elf32_Sym>(addr, name, func_offset);
+  }
+};
+
+class ElfInterface64 : public ElfInterface {
+ public:
+  ElfInterface64(Memory* memory) : ElfInterface(memory) {}
+  virtual ~ElfInterface64() = default;
+
+  bool Init() override {
+    return ElfInterface::ReadAllHeaders<Elf64_Ehdr, Elf64_Phdr, Elf64_Shdr>();
+  }
+
+  void InitHeaders() override { ElfInterface::InitHeadersWithTemplate<uint64_t>(); }
+
+  bool GetSoname(std::string* soname) override {
+    return ElfInterface::GetSonameWithTemplate<Elf64_Dyn>(soname);
+  }
+
+  bool GetFunctionName(uint64_t addr, std::string* name, uint64_t* func_offset) override {
+    return ElfInterface::GetFunctionNameWithTemplate<Elf64_Sym>(addr, name, func_offset);
+  }
+};
+
+}  // namespace unwindstack
+
+#endif  // _LIBUNWINDSTACK_ELF_INTERFACE_H